William Hague has challenged the government to back American plans for a "son of star wars" missile defence system.

Resurrecting Labour's CND spectre and highlighting splits in the government over the £20 billion weapons programme, the Conservative leader committed a Tory government to supporting the plans to create a "shield" against missiles from so-called "rogue" states such as North Korea, Iran, Libya and Iraq. The UK's Fylingdales early warning station would be extensively updated if the system were to get the go-ahead.

The challenge to Labour comes at a key moment in the US presidential transition with the incoming George W Bush seeking to "quickly" develop the defence system opposed by Russia and China and doubted by many of the UK's Nato allies.

Hague is keen to promote his party's strong links with the new US president. He was forced to cancel a visit to meet Bush as it would have broken etiquette because Bush has yet to meet Tony Blair.

A spokesman for the Department of Defence in Washington explained how far development of the system had reached: "The National Missile Defence (NMD) system is being developed to protect the United States against a limited attack by long range ballistic missiles. A decision whether to deploy the fixed, land based system will be made in mid-2000 and will be based on technology development, affordability, the potential threat, international treaty considerations and competing defence priorities.

"A Joint Program Office has been established to give the system director the authority and responsibility to achieve multi-service interoperability. The key NMD components include a ground based interceptor, an X-band radar, Upgraded Early Warning Radars, Battle Management/Command, Control and Communications and space sensor technology."

A UK ministry of defence spokesman told epxNews: "We don't know what Bush proposes to do and he hasn't even been inaugurated as president yet. There has been no definite yes as to whether it will proceed. We will decide on our response as and when we get a declaration. This will come as a formal request and until then we will wait and see. It is premature to state a commitment at this stage."